【作者】 张静；

【导师】 杨军；

【作者基本信息】 合肥工业大学 ， 测试计量技术及仪器， 2016， 硕士

【摘要】 基于液晶材料的相控阵反射阵列天线不仅具有微带反射阵列天线增益高,方向性强,体积小,重量轻的优点,而且可以实现天线波束的扫描功能。这种相控阵反射阵列天线和微带反射阵列天线的区别是利用液晶材料作为微带反射阵列天线的基板,通过外加电场或者磁场改变液晶基板的介电常数调节反射阵面上每个单元的散射相位,从而使反射波在一定范围内实现同相叠加。由于液晶材料在较高的工作频率时仍然能够在宽频带内实现介电常数较宽的调谐范围,因此研究基于液晶材料的相控阵天线对太空探测和太赫兹通信等领域具有重要的意义。本文围绕基于液晶材料的相控阵反射阵列天线的单元特性和阵列设计展开研究。针对基于液晶材料的相控阵反射阵列天线的单元特性,论文首先阐述了微带反射阵列天线的工作原理,相控阵天线的特性参数,反射阵列天线单元移相特性的分析方法,经典移相单元移相功能的实现方式等理论知识。重点分析了基于液晶材料相控阵反射阵列天线的辐射单元的结构组成,相移原理和相移特性,并对经典移相单元和基于液晶材料的移相单元进行仿真分析。在微带反射阵列天线的设计中,文章首先设计了一款Ku波段“回”字形单元结构的微带反射阵列天线,该反射阵列在波束指向角为30度时的增益为20dB。然后,改变“回”字形单元的结构,构造基于液晶材料的“回”字形相控阵反射阵列,从而实现微带反射阵列天线的相控和波束扫描功能,并对该相控阵反射阵列天线的性能进行仿真分析。最终设计出最大波束扫描角为30度的基于液晶材料的“回”字形相控阵反射阵列天线。更多还原

【Abstract】 Reconfigurable reflectarray antennas have benefited from increased attention in the recent past, since they combine some advantages of reflectors and array antennas, such as high gain, strong directivity, small volumes and light weight. Compared with microstrip reflectarrays, the reflectarray antennas based on liquid crystals (LC) can be used for beam reconfiguration or beam scanning through the inclusion of phase-shifter devices that change the phase of reflected field as a function of control signals applied to them.Liquid crystal material in high operating frequency can still achieve high turning rate with wide band. So the study of reflectarray antennas based on LC for space exploration, terahertz communication and so on, has important significance. Researches on the analysis of the reflectarray elements and arrays have been done in this thesis.A Ku band microstrip reflectarray antenna has been designed, and the gain of the reflectarray antenna is 20dB when the antenna in a direction of 30°. To assess the reconfigurability with LC phase shift, different unit cells have been realized and analyzed using CST, showing good performance. Based on this unit cell a reflectarray with beamsteering capability has been designed and realized. The simulations demonstrate that the maximum scanning angle is 30° over a 4.9% bandwidth (336GHz-353GHz) in the low THz range by optimizing the unit cell geometry.更多还原